I collected a bit of algae/sludge on the wet concrete alongside a local klong (canal). It was loaded with Frontonids, tiny single-cell ciliates that gorge themselves on green algae and diatoms. There are plenty of other microorganisms and microanimals in the sample.

At various points in the video there are some stiffer, misshapen organisms. It appears to me that these are Frontonids who have eaten strands of filamentous green algae, and the algae has been bent into a curve around the outside of the Frontonid’s cell. Also note the diatoms inside many of the Frontonids – this food source is one way to distinguish Frontonids from Paramecia.

There are scale bars in the video as the magnification changes. Scale is in microns — there are 1,000 microns in a millimeter. These things are very small. An average human hair is about 100 microns thick.